'Clybourne Park,' coming to San Francisco's American Conservatory Theater, is widely considered his most provocative work.

Ask people what time it is in America, and many will tell you that it's time to keep a civil tongue. The Jan. 8 shootings in Tucson, whatever their motive or ultimate outcome, seem to have stiffened Americans' resolve to lower the volume, mute the stridency and check raw emotions at the threshold of national discourse. The unofficial prime minister of media, Oprah Winfrey, intends to ban "mean-spiritedness" from her new cable network. Even some of the most virulent ideologues at either end of the political spectrum grudgingly concede that maybe they should try to be a little more polite.

All of which make this either the best or worst of times to be Bruce Norris.

It's taken less than five years for Norris, a 50-year-old actor and award-winning playwright, to establish a reputation as a scourge of political correctness, especially as manifested in what some would consider "polite" — read middle-class — society. No matter how careful his mostly liberal white characters are with what they say, strident, even mean-spirited impulses emerge from beneath their temperate, progressive-minded facades.

"People think that the only thing my plays are about is exposing hypocritical liberals," Norris says by phone from his New York home. "And what's usually missing from this assessment, among other things, is that I'm something of a hypocritical liberal too. So I'm not just trying to unmask them. I'm trying to unmask me. I'm part of what I'm trying to expose."

Critics consider "Clybourne Park," Norris' latest work, which begins its first West Coast production this week at San Francisco's American Conservatory Theater, to be perhaps his best and certainly his most provocative play. It takes its title from the fictional, all-white neighborhood in Chicago where, at the end of Lorraine Hansberry's classic 1959 drama "A Raisin in the Sun," the African American Younger family moves from the city's South Side to face a hopeful if uncertain future as Clybourne's first residents of color.

Describing himself as a "whitey" who grew up in an all-white neighborhood in Houston, Norris recalls reading "Raisin" in school and, though affected by its power, confesses that "the only character I could identify with was Karl Lindner," referring to the white community association representative who vainly tries persuading the Youngers not to move.

Lindner reemerges in "Clybourne Park's "first act, set in 1959 at what will soon be the Youngers' new home. The Stollers are the white couple selling the house, and Norris' play speculates as to why they're offering their home for relatively little money despite the objections of Lindner and other neighbors. It turns out their son, a troubled Korean War veteran, committed suicide two years before and the father is especially embittered by the way the community looked down upon (or away from) their son's despair. The acrimony exchanged among Lindner, a neighborhood minister and the Stollers spills onto the couple's black housekeeper and her husband, whom Lindner tries to use as examples as to why African Americans don't want to live in a white residential area.

The second act is set 50 years later in the same house, in the same neighborhood, which has now become a predominantly black, working-class neighborhood. A young white lawyer and his pregnant wife want to buy and remodel the house into a more extravagant home. They meet with Lena, a descendant of the Youngers and her husband, Kevin, to discuss terms for the sale. Disagreement between the couples and their representatives turns into acrimony and accusations of racism, reverse racism, sexism and gentrification

"Not to be too grandiose," Norris says, "but I think in a larger sense, the topic of 'Clybourne Park' is war and territoriality and why we fight over territory. And we do so for incredibly personal, inexplicable, ungraspable, indefinable reasons."

He believes such elemental needs are often couched in euphemism, though Norris' own euphemism for "euphemism" is too salty to repeat here. When, for instance, Lena speaks of maintaining the community's "historically significant" aesthetic, "I think she's using coded language to say, 'Don't build your house. We don't like you here, and we don't want you here.' But she says it with the kind of correct-sounding political rhetoric that is persuasive to those of us on the left while on the right, people go, ' … you! This is what I'm going to do!'"